Process for producing phenoxycarboxylic acid derivative

ABSTRACT

A phenoxycarboxylic acid derivative having the formula ##STR1## wherein R represents ##STR2## and X 1  represents a hydrogen atom, a halogen atom, a lower alkyl group, trifluoromethyl group, nitro group or cyano group and X 2  represents a hydrogen atom, a halogen atom, a lower alkyl group, nitro group or cyano group, R&#39; represents ##STR3## and R 1  and R 2  are the same and different and respectively represent hydrogen atom or a lower alkyl group, is produced by reacting a phenol compound having the formula ##STR4## with a halogen compound having 
     
         X--R&#39; 
    
     wherein X represents a halogen atom in the presence of a base. The reaction is carried out in the presence of a quarternary ammonium salt or a quaternary phosphonium salt in a nonpolar solvent.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a process for producing phenoxycarboxylic acid derivatives useful as agricultural chemicals.

2. Description of the Prior Arts

It has been known that phenoxycarboxylic acid derivatives can be produced by reacting a phenol compound having the formula ##STR5## wherein R represents ##STR6## and X₁ represents a hydrogen atom, a halogen atom, a lower alkyl group, trifluoromethyl group, nitro group or cyano group; X₂ represents a hydrogen atom, a halogen atom, a lower alkyl group, nitro group or cyano group, with a halogen compound having the formula

    X--R'

wherein R' represents ##STR7## and R₁ and R₂ respectively represent a hydrogen atom or a lower alkyl group and X represents a halogen atom, in a solvent such as ketones e.g. acetone, butanone and methyl ethyl ketone; ethers e.g. tetrahydrofuran, diethyl ether, methyl butyl ether, ethyleneglycol dimethyl ether; dimethylformamide, dimethylacetamide, dimethylsulfoxide, benzene, toluene and hexane, in the presence of a dehydrogenhalide agent of an alkali metal compound such as sodium or potassium compound or an alkaline earth metal compound such as calcium or magnesium compound. This is disclosed in Japanese Unexamined Patent Publication No. 22432/1973, 125228/1976, 32730/1976, and 87173/1977.

However, a dehydrogenhalidation of the halogen compound is caused by this process. Thus, a large amount of the halogen compound should be used and a large amount of the by-products is produced to cause low yield of the object compound.

The inventors have studied to obtain a phenoxycarboxylic acid derivative having high purity in high yield.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a process for producing a phenoxycarboxylic acid derivative having high purity in high yield by preventing side reactions.

The foregoing and other objects of the present invention have been attained by reacting a phenol compound having the formula ##STR8## wherein R represents ##STR9## and X₁ represents a hydrogen atom, a halogen atom, a lower alkyl group, trifluoromethyl group, nitro group or cyano group; X₂ represents a hydrogen atom, a halogen atom, a lower alkyl group, nitro group or cyano group, with a halogen compound having the formula

    X--R'                                                      (II)

wherein R' represents ##STR10## and R₁ and R₂ respectively represent a hydrogen atom or a lower alkyl group; and X represents a halogen atom, in the presence of a quaternary ammonium salt or a quaternary phosphonium salt and in the presence of a base of an alkali metal compound or an alkaline earth metal compound to produce a phenoxycarboxylic acid derivative having the formula wherein R and R' are defined above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The phenol compounds having the formula (I) used in the present invention are the compounds having the formula ##STR11## wherein X₁ and X₂ is the same or different and respectively represents a hydrogen atom; a halogen atom such as chlorine, bromine, fluorine or iodine atom; a lower alkyl group such as methyl, ethyl, i-propyl or t-butyl group; trifluoromethyl group; nitro group; or cyano group.

Suitable phenol compounds (I) include 4-phenoxyphenol, 4-(2-chlorophenoxy)phenol, 4-(4-chlorophenoxy)phenol, 4-(4-bromophenoxy)phenol, 4-(3-methylphenoxy)phenol, 4-(4-methylphenoxy)phenol, 4-(3-trifluoromethylphenoxy)phenol, 4-(4-trifluoromethylphenoxy)phenol, 4-(2,5-dichlorophenoxy)phenol, 4-(3,4-dichlorophenoxy)phenol, 4-(3,5-dichlorophenoxy)phenol, 4-(4-chloro-3-methylphenoxy)phenol, 4-(4-chloro-2-methylphenoxy)phenol, 4-(2-bromo-4-trifluoromethylphenoxy)phenol, 4-(2-chloro-4-trifluoromethylphenoxy)phenol, 4-(4-chloro-2-nitrophenoxy)phenol, 4-(4-chloro-2-cyanophenoxy)phenol, 4-(5-methyl-2-isopropylphenoxy)phenol, 4-(4-trifluoromethyl-2-nitrophenoxy)phenol, 4-(2-cyano-4-trifluoromethylphenoxy)phenol, 4-(4-cyano-2-nitrophenoxy)phenol, 4-(5-chloropyridyl-2-oxy)phenol, 4-(5-bromopyridyl-2-oxy)phenol, 4-(5-iodopyridyl-2-oxy)phenol, 4-(3,5-dichloropyridyl-2-oxy)phenol, 4-(3,5-dibromopyridyl-2-oxy)phenol and 4-(3,5-diiodopyridyl-2-oxy)phenol.

The halogen compounds used in the present invention are the compounds having the formula (II) wherein R' represents ##STR12## and R₁ and R₂ respectively represent a hydrogen atom; a lower alkyl group such as methyl, ethyl, n-propyl, i-propyl, n-butyl, or i-butyl group; X represents a halogen atom such as chlorine, bromine or iodine atom.

Suitable halogen compounds (II) include 2-bromopropanoic acid, 2-chloropropanoic acid, methyl 2-bromopropanoate, ethyl 2-bromopropanoate, ethyl 2-chloropropanoate, propyl 2-bromopropanoate, propyl 2-chloropropanoate, butyl 2-bromopropanoate, butyl 2-chloropropanoate, 2-bromobutanoic acid, 2-chlorobutanoic acid, methyl 2-bromobutanoate, methyl 2-chlorobutanoate, ethyl 2-bromobutanoate, ethyl 2-chlorobutanoate, propyl 2-bromobutanoate, propyl 2-chlorobutanoate, butyl 2-bromobutanoate, butyl 2-chlorobutanoate, 2-bromopentanoic acid, 2-chloropentanoic acid, methyl 2-bromopentanoate, methyl 2-chloropentanoate, ethyl 2-bromopentanoate, ethyl 2-chloropentanoate, propyl 2-bromopentanoate, propyl 2-chloropentanoate, butyl 2-bromopentanoate, butyl 2-chloropentanoate, 4-bromopentanoic acid, 4-chloropentanoic acid, methyl 4-bromopentanoate, methyl 4-chloropentanoate, ethyl 4-bromopentanoate, ethyl 4-chloropentanoate, propyl 4-bromopentanoate, propyl 4-chloropentanoate, butyl 4-bromopentanoate, butyl 4-chloropentanoate, 4-bromohexanoic acid, 4-chlorohexanoic acid, methyl 4-bromohexanoate, methyl 4-chlorohexanoate, ethyl 4-bromohexanoate, ethyl 4-chlorohexanoate, propyl 4-bromohexanoate, propyl 4-chlorohexanoate, butyl 4-bromohexanoate, butyl 4-chlorohexanoate, 4-bromoheptanoic acid, 4-chloroheptanoic acid, methyl 4-bromoheptanoate, methyl 4-chloroheptanoate, ethyl 4-bromoheptanoate, ethyl 4-chloroheptanoate, propyl 4-chloroheptanoate, butyl 4-bromoheptanoate, butyl 4-chloroheptanoate, 4-bromo-2-pentenoic acid, 4-chloro-2-pentenoic acid, methyl 4-bromo-2-pentenoate, methyl-4-chloro-2-pentenoate, ethyl 4-bromo-2-pentenoate ethyl 4-chloro-2-pentenoate, propyl 4-bromo-2-pentenoate, propyl 4-chloro-2-pentenoate, butyl 4-bromo-2-pentenoate, butyl 4-chloro-2-pentenoate, 4-bromo-2-hexenoic acid, 4-chloro-2-hexenoic acid, methyl-4-bromo-2-hexenoate, methyl 4-chloro-2-hexenoate, ethyl 4-bromo-2-hexenoate, ethyl 4-chloro-2-hexenoate, propyl 4-bromo-2-hexenoate, propyl 4-chloro-2-hexenoate, butyl 4-bromo-2-hexenoate, butyl 4-chloro-2-hexenoate, 4-bromo-2-heptenoic acid, 4-chloro-2-heptenoic acid, methyl 4-bromo-2-heptenoate, methyl 4-chloro-2-heptenoate, ethyl 4-bromo-2-heptenoate, ethyl 4-chloro-2-heptenoate, propyl 4-bromo-2-heptenoate, propyl 4-chloro-2-heptenoate, butyl 4-bromo-2-heptenoate, butyl 4-chloro-2-heptenoate, 4-chloro-3-methyl-2-butenoic acid, 4-bromo-3-ethyl-2-butenoic acid, methyl 4-chloro-3-methyl-2-butenoate and propyl 4-bromo-3-methyl-2-butenoate.

The quaternary ammonium salts or the quaternary phosphonium salts include benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts, tetraalkylphosphonium salts, triphenylalkylphosphonium salts and triphenylbenzylphosphonium salts such as benzyltriethylammonium bromide, benzyltributylammonium chloride, benzyltriamylammonium chloride, benzyltrioctylammonium chloride, trioctylmethylammonium chloride, isobutyltributylammonium bromide, hexadecyltributylphosphonium bromide, tetrapropylammonium bromide, tetrabutylammonium chloride, tetraamylammonium bromide, tetraamylammonium chloride, tetrahexylammonium bromide and tetrabutylphosphonium chloride. It is preferable to select the quaternary ammonium salt or the quaternary phosphonium salt from benzyl tri-C₁ -C₁₆ alkylammonium salts, tetra-C₁ -C₁₆ alkylammonium salts, triphenylbenzylphosphonium salts, benzyl tri-C₁ -C₁₆ alkylphosphonium salts, tetra-C₁ -C₁₆ alkylphosphonium salts, and triphenyl C₁ -C₁₆ alkylphosphonium salts.

The alkali metal compounds or the alkaline earth metal compounds used in the present invention are the bases such as potassium hydroxide, potassium carbonate, sodium hydroxide, sodium carbonate, calcium hydroxide and magnesium oxide. It is optimum to use sodium carbonate (bicarbonate) or potassium carbonate (bicarbonate).

It is preferable to use a solvent so as to smoothly result the reaction. It is preferable to use a solvent being stable to the alkali metal compound or the alkaline earth metal compound, and especially an insert nonpolar solvent such as aromatic or aliphatic hydrocarbons and aromatic or aliphatic halohydrocarbons.

The reaction of the present invention is carried out by reacting the phenol compound having the formula (I) with the halogen compound having the formula (II) in the presence of the quaternary ammonium salt or the quaternary phosphonium salt, and in the presence of a base of the alkali metal compound or the alkaline earth metal compound in a solvent, by heating and stirring them.

After the reaction, an oil phase is separated from the reaction mixture by a phase separation and washed with an acid and with water and treated by a distillation or a recrystallization to obtain the object compound of the phenoxycarboxylc acid derivative (III) having high purity in high yield.

The halogen compound (II) is used at a molar ratio of 1.0 to 1.5 preferably 1.05 to 1.1 based on the phenol compound (I).

The quaternary ammonium salt or the quaternary phosphonium salt is used at a molar ratio of 0.005 to 0.05, preferably 0.008 to 0.015 based on the phenol compound (I).

The base of the alkali metal compound or the alkaline earth compound is used at a molar ratio of 0.5 to 1.5 based on the phenol compound (I), in a form of an aqueous solution at a desired concentration.

The reaction temperature is in a range of 50° to 90° C. preferably 60° to 80° C. The reaction time is depending upon the reaction temperature and is usually in a range of 4 to 8 hours.

In the reaction of the phenol compound (I) with the halogen compound (II), in the present invention, the dehydrogenhalide reaction of the halogen compound itself is prevented to prevent the side reactions by using at least one of the quaternary ammonium salts and the quaternary phosphonium salts such as benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts, tetralkylphosphonium salts, benzyltriphenylphosphonium salts, alkyl triphenylphosphonium salts whereby the phenoxycarboxylic acid derivative (III) having high purity can be obtained in high yield.

The process of the present invention attain excellent advantages that the phenoxycarboxylic acid derivative having high purity can be easily produced in high yield and the side reaction can be remarkably decreased.

The present invention will be further illustrated by certain examples and references which are provided for purposes of illustration only and are not intended to be limiting the present invention.

EXAMPLE 1

In a reactor, 100 ml of chlorobenzene and 100 ml of water were charged and then, 95.3 g (0.375 mole) of 4-(4-trifluoromethylphenoxy)phenol, 85.4 g (0.412 mole) of ethyl 4-bromo-2-pentenoate, 39.0 g (0.281 mole) of potassium carbonate and 1.1 g (0.00375 mole) of tributylethyl ammonium bromide were added. The mixture was refluxed with stirring for 6 hours to react them, and the water phase was removed and the organic phase was washed with 5% hydrochloric acid and with water and then, chlorobenzene, ethyl 4-bromo-2-pentenoate and low boiling by-products were distilled off at 100° C. under a reduced pressure of 0.02 to 0.05 mmHg to obtain 137.0 g of ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate. The yield was 96.0%.

EXAMPLE 2

In a reactor, 100 ml of chlorobenzene and 100 ml of water were charged and 95.3 g (0.375 mole) of 4-(4-trifluoromethylphenoxy)phenol, 73.7 g (0.412 mole) of 4-bromo-2-pentenoate, 78.0 g (0.56 mole) of potassium carbonate and 1.1 g (0.00375 mole) of tributylethylammonium bromide were added. The mixture was refluxed with stirring for 6 hours. The reaction mixture was cooled to the room temperature and conc. hydrochloric acid was added to the reaction mixture with stirring to be acidic. The water phase was separated and the organic phase was washed with water and chlorobenzene was distilled off at 100° C. under a reduced pressure of 0.02 to 0.05 mmHg to obtain 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoic acid. The yield was 91.2%.

REFERENCE 1

In accordance with the process of Example 1 except that tributylethylammonium bromide was not incorporated, the mixture was refluxed with stirring for 6 hours and the reaction mixture was cooled to the room temperature and 15.0 g (0.375 mole) of sodium hydroxide was added and the mixture was further stirred for 30 minutes and the mixture was further treated to obtain 44.5 g of ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate. The yield was 31.2%.

REFERENCE 2

In a reactor, 100 ml of ethanol was charged and 95.3 g (0.375 mole) of 4-(4-trifluoromethylphenoxy)phenol, 85.4 g (0.412 mole) of ethyl 4-bromo-2-pentenoate and 39.0 g (0.281 mole) of potassium carbonate were added. The mixture was refluxed with stirring for 6 hours to react them. Ethanol was distilled off and 100 ml of chlorobenzene and 100 ml of water were added and the mixture was stirred at the room temperature for 30 minutes. The water phase was separated and the organic phase was washed with 5% hydrochloric acid and with water and then, chlorobenzene, ethyl 4-bromo-2-pentenoate and low boiling by-products were distilled off under a reduced pressure to obtain 10.47 g of ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate. The yield was 73.5%.

EXAMPLES 3 TO 39

In accordance with the process of Example 1 except using the phenol compounds and the halogen compounds shown in Table 1 instead of 4-(4-trifluoromethylphenoxy)phenol and ethyl 4-bromo-2-pentenoate, each reaction was carried out. The results are shown in Table 1.

                  TABLE 1                                                          ______________________________________                                         Ex-                                                                            am-  Starting material                                                         ple  Phenol compound    Halogen compound                                       ______________________________________                                         3    4-(4-trifluoromethylphenoxy)                                                                      ethyl 4-brono-2-                                            phenol             pentenoate                                             4    4-(4-trifluoromethylphenoxy)                                                                      4-bromo-2-pentenoic acid                                    phenol                                                                    5    4-(4-trifluoromethylphenoxy)                                                                      2-bromopropanoic acid                                       phenol                                                                    6    4-(4-trifluoromethylphenoxy)                                                                      ethyl 4-chloropentanoate                                    phenol                                                                    7    4-(4-trifluoromethylphenoxy)                                                                      ethyl 4-bromo-2-                                            phenol             heptenoate                                             8    4-(4-trifluoromethylphenoxy)                                                                      octyl 4-bromo-2-penteno-                                    phenol             ate                                                    9    4-(3-trifluoromethyl-                                                                             ethyl 4-bromo-2-                                            phenoxy) phenol    pentenoate                                             10   4-(2-chloro-4-trifluoro-                                                                          4-chloro-2-pentenoic acid                                   methylphenoxy) phenol                                                     11   4-(2-nitro-4-trifluoromethyl-                                                                     ethyl 4-bromo-2-                                            phenoxy) phenol    pentenoate                                             12   4-(2-bromo-4-      ethyl 4-bromo-2-                                            trifluoromethylphenoxy)                                                                           pentenoate                                                  phenol                                                                    13   4-phenoxyphenol    4-bromo-2-pentenoic acid                               14   4-(2-chlorophenoxy)                                                                               butyl 4-bromo-2-                                            phenol             pentenoate                                             15   4-(4-cyanophenoxy) phenol                                                                         ethyl 4-bromo-2-                                                               pentenoate                                             16   4-(2,4-dichlorophenoxy)                                                                           ethyl 2-chloropropanoate                                    phenol                                                                    17   4-(2-nitro-4-chlorophenoxy)                                                                       isopropyl 2-bromo-                                          phenol             propanoate                                             18   4-(2-chloro-4-nitro-                                                                              ethyl 2-bromoacetate                                        phenoxy) phenol                                                           19   4-(2-nitro-4-chloro-                                                                              ethyl 4-bromo-2-                                            phenoxy) phenol    butenoate                                              20   4-(4-nitrophenoxy) phenol                                                                         ethyl 2-bromobutanoate                                 21   4-(4-bromophenoxy) phenol                                                                         isopropyl 4-bromo-2-                                                           pentenoate                                             22   4-(3,5-dichloropyridyl-                                                                           ethyl 2-bromopropanoate                                     2-oxy) phenol                                                             23   4-(3,5-dichloropyridyl-                                                                           butyl 4-bromo-2-                                            2-oxy) phenol      pentenoate                                             24   4-(5-nitropyridyl-2-                                                                              ethyl 2-bromopropanoate                                     oxy) phenol                                                               25   4-(5-nitropyridyl-2-                                                                              ethyl 4-bromo-2-                                            oxy) phenol        pentenoate                                             26   4-phenoxyphenol    methyl 4-chloro-3-                                                             methyl-2-butenoate                                     27   4-(4-chlorophenoxy) phenol                                                                        isopropyl 4-bromo-3-                                                           methyl-2-butenoate                                     28   4-(5-methyl-2-isopropyl-                                                                          2-chloropropanoic acid                                      phenoxy) phenol                                                           29   4-(3-methylphenoxy) phenol                                                                        2-chloropropanoic acid                                 30   4-(4-chloro-3-methylphenoxy)                                                                      2-chloropropanioc acid                                      phenol                                                                    31   4-(4-trifluoromethyl-                                                                             isobutyl 2-bromo-                                           phenoxy) phenol    propanoate                                             32   4-(2-bromo-4-trifluoro-                                                                           ethyl 2-bromo-                                              methylphenoxy) phenol                                                                             propanoate                                             33   4-(5-bromopyridyl-2-oxy)                                                                          2-chloroacetic acid                                         phenol                                                                    34   4-(3,5-dibromopyridyl-                                                                            2-bromopropanoic acid                                       2-oxy) phenol                                                             35   4-(3,5-dichloropyridyl-                                                                           methyl 2-chloroacetate                                      2-oxy) phenol                                                             36   4-(5-chloropyridyl-2-                                                                             methyl 2-bromo-                                             oxy) phenol        propanoate                                             37   4-(3,5-diiodopyridyl-                                                                             ethyl 2-bromo-                                              2-oxy) phenol      propanoate                                             ______________________________________                                    

                  TABLE 1                                                          ______________________________________                                         Ex-  Product                                                                   am-  Phenoxycarboxylic acid                                                                              Physical   Yield                                     ple  derivative           property   (%)                                       ______________________________________                                         3    ethyl 4-[4-(4-trifluoromethyl-                                                 phenoxy) phenoxy]-2-penteno-                                                                        n.sub.D.sup.20 1.5195                                                                     96.0                                           ate                                                                       4    4-[4-(4-trifluoromethyl-                                                       phenoxy) phenoxy]-2-pentenoic                                                                       n.sub.D.sup.20 1.5119                                                                     91.2                                           acid                                                                      5    2-[4-(4-trifluoromethylphenoxy)                                                                     m.p.                                                      phenoxy]propanoic acid                                                                              136-138° C.                                                                        90.5                                      6    ethyl 4-[4-(4-trifluoromethyl-                                                 phenoxy) phenoxy]pentanoate                                                                         n.sub.D.sup.20 1.5080                                                                     94.5                                      7    ethyl 4-[4-(4-trifluoromethyl-                                                 phenoxy) phenoxy]pentanoate                                                                         n.sub.D.sup.20 1.5103                                                                     95.0                                      8    octyl 4-[4-(4-trifluoromethyl-                                                 phenoxy) phenoxy]-2-pentenoate                                                                      n.sub.D.sup.20 1.5045                                                                     96.5                                      9    ethyl 4-[4-(3-trifluoromethyl-                                                 phenoxy) phenoxy]-2-pentenoate                                                                      n.sub.D.sup.20 1.5155                                                                     96.0                                      10   4-[4-(2-chloro-4-trifluoro-                                                                         m.p.                                                      methylphenoxy) phenoxy]-2-                                                                          88-89° C.                                                                          87.3                                           pentenoic acid                                                            11   ethyl 4-[4-(2-nitro-4-trifluoro-                                               methylphenoxy) phenoxy]-2-                                                                          n.sub.D.sup.20 1.5343                                                                     95.6                                           pentenoate                                                                12   ethyl 4-[4-(2-bromo-4-trifluoro-                                               methylphenoxy) phenoxy]-2-                                                                          n.sub.D.sup.20 1.5341                                                                     96.0                                           pentenoate                                                                13   4-(4-phenoxyphenoxy)-2-                                                                             m.p.                                                      pentenoate           113-114° C.                                                                        94.7                                      14   butyl 4-[4-(2-chlorophenoxy)                                                   phenoxy]-2-pentenoate                                                                               n.sub.D.sup.20 1.5547                                                                     95.1                                      15   ethyl 4-[4-(4-cyanophenoxy)                                                    phenoxy]-2-pentenoate                                                                               n.sub.D.sup.20 1.5625                                                                     93.7                                      16   ethyl 2-[4-(2,4-dichlorophenoxy)                                               phenoxy]propanoate   n.sub.D.sup.20 1.5601                                                                     90.0                                      17   isopropyl 2-[4-(2-nitro-4-                                                     chlorophenoxy) phenoxy]pro-                                                                         n.sub.D.sup. 20 1.5605                                                                    97.1                                           panoate                                                                   18   ethyl 2-[4-(2-chloro-4-nitro-                                                                       m.p.                                                      phenoxy) phenoxy]acetate                                                                            92-95° C.                                                                          97.0                                      19   ethyl 4-[4-(2-nitro-4-chloro-                                                  phenoxy) phenoxy]-2-butenoate                                                                       n.sub.D.sup.20 1.5790                                                                     97.5                                      20   ethyl 2-[2-(4-nitrophenoxy)                                                    phenoxy]butanoate    n.sub.D.sup.20 1.5701                                                                     94.3                                      21   isopropyl 4-[4-(4-bromophenoxy)                                                phenoxy]-2-pentenoate                                                                               n.sub.D.sup.20 1.5724                                                                     95.0                                      22   ethyl 2-[4-(3,5-dichloropyridyl-                                               2-oxy) phenoxy]propanoate                                                                           n.sub.D.sup.20 1.5603                                                                     90.2                                      23   butyl 4-[4-(3,5-dichloropyridyl-                                               2-oxy) phenoxy]-2-pentenoate                                                                        n.sub.D.sup.20 1.5565                                                                     92.7                                      24   ethyl 2-[4-(5-nitropyridyl-2-                                                  oxy) phenoxy]propanoate                                                                             n.sub.D.sup.20 1.5557                                                                     91.3                                      25   ethyl 4-[4-(5-nitropyridyl-2-                                                  oxy) phenoxy]-2-pentenoate                                                                          n.sub.D.sup.20 1.5684                                                                     89.2                                      26   methyl 4-(4-phenoxyphenoxy)-3-                                                                      m.p.                                                      methy-2-butenoate    55-56° C.                                                                          91.0                                      27   isopropyl 4-[4-(4-chlorophenoxy)                                                                    m.p.                                                      phenoxy]-3-methyl-2-butenoate                                                                       49-50° C.                                                                          98.0                                      28   2-[4-(5-methyl-2-isopropylphe-                                                                      m.p.                                                      noxy) phenoxy]propanoic acid                                                                        91-92° C.                                                                          91.1                                      29   2-[4-(3-methylphenoxy) phenoxy]                                                                     m.p.                                                      propanoic acid       78-79° C.                                                                          92.5                                      30   2-[4-(4-chloro-3-methylphenoxy)                                                                     m.p.                                                      phenoxy]propanoic acid                                                                              128-129° C.                                                                        90.5                                      31   isobutyl 2-[4-(4-trifluoro-                                                                         m.p.                                                      methylphenoxy) phenoxy]propano-                                                                     55-57° C.                                                                          90.8                                           ate                                                                       32   ethyl 2-[4-(2-bromo-4-trifluoro-                                               methylphenoxy) phenoxy]propano-                                                                     n.sub.D.sup.20 1.5541                                                                     91.1                                           ate                                                                       33   2-[4-(5-bromopyridyl-2-oxy)                                                                         m.p.                                                      phenoxy]acetic acid  130-132° C.                                                                        93.1                                      34   2-[4-(3,5-dibromopyridyl-2-                                                                         m.p.                                                      oxy) phenoxy]propanoic acid                                                                         68-70° C.                                                                          90.3                                      35   methyl 2-[4-(3,5-dichloropyridyl-                                                                   m.p.                                                      2-oxy) phenoxy]acetate                                                                              52-54° C.                                                                          93.7                                      36   methyl 2-[4-(5-chloropyridyl-                                                                       m.p.                                                      2-oxy) phenoxy]propanoate                                                                           88-90° C.                                                                          92.0                                      37   ethyl 2-[4-(3,5-diiodopyridyl-                                                                      m.p.                                                      2-oxy) phenoxy]propanoate                                                                           85-87° C.                                                                          90.0                                      ______________________________________                                    

EXAMPLES 38 TO 48

In accordance with the process of Example 1 except replacing tributylethylammonium bromide by the other quaternary ammonium salt or phosphonium salt shown in Table 2, ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate was produced. The results are shown in Table 2.

                  TABLE 2                                                          ______________________________________                                         Example  Quaternary salt        Yield (%)                                      ______________________________________                                         38       benzyltrimethylammonium chloride                                                                      93.5                                           39       benzyltriethylammonium bromide                                                                        95.2                                           40       benzyltrioctylammonium chloride                                                                       94.1                                           41       benzyltriphenylphosphonium chloride                                                                   94.7                                           42       tetraethylammonium bromide                                                                            94.5                                           43       tetrabutylammonium bromide                                                                            94.5                                           44       tetrahexylammonium bromide                                                                            93.2                                           45       trioctylmethylammonium chloride                                                                       94.1                                           46       tetrabutylphosphonium bromide                                                                         95.0                                           47       methyltriphenylphosphonium bromide                                                                    94.7                                           48       butyltriphenylphosphonium bromide                                                                     94.3                                           ______________________________________                                    

EXAMPLES 49 TO 56

In accordance with the process of Example 1 except replacing chlorobenzene by the other nonpolar solvent shown in Table 3, ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate was produced. The results are shown in Table 3.

                  TABLE 3                                                          ______________________________________                                         Example     Solvent             Yield (%)                                      ______________________________________                                         49          benzene             95.0                                           50          toluene             95.1                                           51          xylene              94.7                                           52          dichlorobenzene     94.5                                           53          chloroform          94.0                                           54          carbon tetrachloride                                                                               94.1                                           55          n-hexane            94.0                                           56          cyclohexane         93.7                                           ______________________________________                                    

EXAMPLE 57

In accordance with the process of Example 1 except using 67.0 g (0.412 mole) ethyl 4-chloro-2-pentenoate instead of 85.4 g (0.412 mole) of ethyl 4-bromo-2-pentenoate, ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate was obtained. The yield was 83.4%. 

We claim:
 1. In a process for producing a phenoxycarboxylic acid derivative having the formula ##STR13## wherein R represents ##STR14## and X₁ represents a hydrogen atom, a halogen atom, a lower alkyl group, trifluoromethyl group, nitro group or cyano group and X₂ represents a hydrogen atom, a halogen atom, a lower alkyl group, nitro group or cyano group, R' represents ##STR15## And R₁ and R₂ are the same and different and respectively represent hydrogen atom or a lower alkyl group, by reacting a phenol compound having the formula ##STR16## with a halogen compound having

    X--R'                                                      (II)

wherein X represents a halogen atom, in the presence of a base the improvement comprising carrying out the reaction in the presence of a quaternary phosphonium salt selected from the group consisting of benzyltrialkylammonium salts, benzyltrialylphosphonium salts, tetraalkylammonium salts, tetraalkylphosphonium salts, triphenylalkylphosphonium salts and triphenylbenzylphosphonium salts in a nonpolar solvent at 50° to 90° C., the molar ratio of the quaternary ammonium salt or quaternary phosphonium salt to the phenol compound is from 0.005 to 0.05 and the molar ratio of the base to the phenol compound is from 0.05 to 1.5.
 2. A process according to claim 1 wherein said base is an alkali metal compound or an alkaline earth metal compound. 